It all depends on your playstyle. I got to diamond by focusing on what I was good at personally. You just need to play around in every lane and figure out what you like.
Top- Mainly focused on 1v1 and csing. You want to be able to play fighters, as well as some tanks. Good map awareness is important as you usually have teleport and engage for the team. A lot of champ diversity top, usually somewhat snowbally.
Jungle- Focuses on macro and game knowledge. You don't need to be good at csing, just knowing when to gank and how to duel and take objectives. More "laid back" in my opinion, and is best for people that want to carry the team to victory through strategy or just dominating the other jungler.
Mid- Focuses on mechanics and being able to use the map. This is probably the most demanding role, because you need to be able to cs well, harass the enemy, avoid ganks and roam. Good champ diversity also, but very volatile lane. If you are more about mechanics and winning your lane or roaming, mid is best
ADC- If you like to 1v5 or teamfight really well, adc is best. Focuses on CSing and teamfight positioning. Somewhat demanding role for the more flashy player that likes to be able to kill everyone, but can suck if you fall behind.
Support- Likes focusing on helping the team. Essentially a jungler that focuses on vision and peeling/engaging. Not that demanding, but you need to have decent game knowlege and know how to start fights or peel, and ward.